Question 1

A 45-year-old man with a history of alcohol use disorder (6 months sober) reports persistent insomnia that is a significant relapse trigger. He asks his psychiatrist for "something to help me sleep." He has tried melatonin without benefit. His psychiatrist wants to avoid medications with abuse potential or dependence risk. Which of the following is the most appropriate choice?

Accepted Answer

This tests insomnia management in a substance use population. Zolpidem (answer A) is a Z-drug with GABA-A activity, abuse potential, and Schedule IV status; it is specifically risky in a patient with alcohol use disorder due to cross-tolerance and reinforcing effects. Lorazepam (answer B) is a benzodiazepine with the same concerns amplified. Gabapentin (answer D) is sometimes considered in substance use populations, but it has emerging misuse and diversion concerns, additive sedation risk, and limited evidence as a primary insomnia agent. Suvorexant provides effective insomnia treatment through a mechanism that does not engage the reward pathways implicated in substance use disorders.

Question 2

A 28-year-old woman with narcolepsy type 1 (confirmed by CSF hypocretin levels below 110 pg/mL) is treated with modafinil for daytime sleepiness. She also complains of difficulty falling asleep at night. She asks about suvorexant, which her friend uses for insomnia. Is suvorexant appropriate?

Accepted Answer

This is the mechanism question. Suvorexant's contraindication in narcolepsy is not an arbitrary labeling decision. It is a direct consequence of the pharmacological mechanism. The student who understands why suvorexant is contraindicated in narcolepsy understands the drug. Answers A and C both incorrectly assume suvorexant is safe in this population. Answer D incorrectly attributes the concern to a drug interaction rather than the fundamental mechanism. The CSF hypocretin level in the stem confirms orexin deficiency, making the contraindication absolute.

Question 3

A 52-year-old man is started on suvorexant 10mg for chronic insomnia. He is also taking fluconazole 200mg daily for a fungal infection. After the first night, he reports severe next-day drowsiness, difficulty concentrating, and nearly falling asleep while driving. What is the most likely cause?

Accepted Answer

This tests the CYP3A4 interaction that is clinically relevant for suvorexant (and mirrors the CYP3A4 interaction profile taught on the buspirone page). Fluconazole is a moderate CYP3A4 inhibitor that reduces suvorexant metabolism, raising levels and prolonging orexin receptor blockade. The labeling already accounts for this by capping the dose at 10mg with moderate inhibitors, but some patients will still be sensitive even at the adjusted dose. The critical safety point: next-day somnolence with suvorexant impairs driving, and any CYP3A4 inhibitor increases this risk.

Suvorexant

Side Effects Worth Knowing

Next-Day Somnolence

Headache

Sleep Paralysis

Hypnagogic/Hypnopompic Hallucinations

Abnormal Dreams

Complex Sleep Behaviors

See This Medication in Action

References & Further Reading